Make other controllers 'available' in pose mode?
The easiest option here is to disable &quot;Lock object modes&quot;, on the main Edit menu.  If you do this, you'll still be able to select (and manipulate) objects while in Pose mode.
If there's a reason you don't want to do that, an alternative is to parent (bone parent) your mesh controllers to new bones.  If you really want, you could even give these bones custom shapes, referencing your mesh controllers, and then hide the mesh controllers on some distant collection....